RE: row filtering for logical replication

On Wednesday, December 8, 2021 7:52 PM Ajin Cherian <itsajin(at)gmail(dot)com>
> On Tue, Dec 7, 2021 at 5:36 PM Peter Smith <smithpb2250(at)gmail(dot)com> wrote:
> >
> > We were mid-way putting together the next v45* when your latest
> > attachment was posted over the weekend. So we will proceed with our
> > original plan to post our v45* (tomorrow).
> >
> > After v45* is posted we will pause to find what are all the
> > differences between your unified patch and our v45* patch set. Our
> > intention is to integrate as many improvements as possible from your
> > changes into the v46* etc that will follow tomorrow’s v45*. On some
> > points, we will most likely need further discussion.
>
>
> Posting an update for review comments, using contributions majorly from
> Peter Smith.
> I've also included changes based on Euler's combined patch, specially changes
> to documentation and test cases.
> I have left out Hou-san's 0005, in this patch-set. Hou-san will provide a rebased
> update based on this.
>
> This patch addresses the following review comments:

Hi,

Thanks for updating the patch.
I noticed a possible issue.

+ /* Check row filter. */
+ if (!pgoutput_row_filter(data, relation, oldtuple, NULL, relentry))
+ break;
+
+ maybe_send_schema(ctx, change, relation, relentry);
+
/* Switch relation if publishing via root. */
if (relentry->publish_as_relid != RelationGetRelid(relation))
{
...
/* Convert tuple if needed. */
if (relentry->map)
tuple = execute_attr_map_tuple(tuple, relentry->map);

Currently, we execute the row filter before converting the tuple, I think it could
get wrong result if we are executing a parent table's row filter and the column
order of the parent table is different from the child table. For example:

----
create table parent(a int primary key, b int) partition by range (a);
create table child (b int, a int primary key);
alter table parent attach partition child default;
create publication pub for table parent where(a>10) with(PUBLISH_VIA_PARTITION_ROOT);

The column number of 'a' is '1' in filter expression while column 'a' is the
second one in the original tuple. I think we might need to execute the filter
expression after converting.

Best regards,
Hou zj